Field of the Invention
The present invention relates to image shake correction control using detected information about shaking applied to a device and a motion vector that is calculated from an image signal.
Description of the Related Art
In image pickup apparatuses, accompanying the miniaturization of the apparatus and the higher magnification of optical systems, shaking such as hand shaking remarkably affects an image, and accordingly an image pickup apparatus that includes an image shake correction function has been proposed. The image shake correction function is a function that corrects the image shake of an image due to shaking of the image pickup apparatus. As techniques for improving a correction accuracy of the image shake, there is a method that uses a process that detects a motion vector detected from deviation between a plurality of images, in addition to the use of a shake detection sensor that detects shaking. In an apparatus disclosed in Japanese Patent Application Laid-Open Publication No. 2005-203861, an output gain of the shake detection sensor is changed by using motion vector information, the detected deviation from an actual shake amount by the shake detection sensor is then corrected, and as a result, the image shake correction effect can be enhanced.
However, the technique of Japanese Patent Application Laid-Open Publication No. 2005-203861 only changes the output gain of the shake detection sensor, and simply corrects the deviation of the output gain (sensitivity deviation) of the shake detection sensor against the actual shake amount. In addition to the deviation of the output gain of the shake detection sensor, reasons for decreasing the correction accuracy of the image shake are as follows:                Deviation in the phase of the output of the shake detection sensor with respect to the actual shake;        Variations in mechanical characteristics of the image shake correction device that are driven based on a target signal that has been calculated from the output of the shake detection sensor (including variations of frequency response); and        Variations of characteristics of a mechanical unit due to temperature fluctuations or the like in photographing environment.        
Therefore, it is difficult to improve the image shake correction accuracy by only changing the output gain of the shake detection sensor.